The invention relates to improvements in clamps for pipes and similar cylindrical objects. More particularly, the invention relates to improvements in clamps of the type wherein the pipe is confined between a substantially C-shaped holder and a substantially U-shaped confining member and the legs of the U-shaped confining member cooperate with the end portions of the C-shaped holder to releasably hold the pipe between them.
It is already known to construct the holder of a pipe clamp in such a way that it extends along an arc of more than 180 degrees and that its end portions are disposed between the legs of the confining member. The holder and/or the confining member is elastic so that the end portions of the holder are biased against the respective legs or vice versa to ensure that the mating male and female detent means on the legs and on the end portions are held against accidental separation or against separation in response to the application of relatively small deforming forces.
In accordance with a presently known proposal, the clamp is made of a plastic material and the end portions of the holder bear against the external surface of the confined pipe. This creates problems, especially if the pipe is supported by two or more spaced-apart clamps. Thus, if the pipe tends to expand radially as a result of heating or to expand or contract longitudinally as a result of heating or cooling and/or if the pipe is shifted axially, it tends to buckle or bend between neighboring clamps and/or to detach the clamps from their carriers and/or to disengage the confining members from the holders of the clamps.
German Utility Model No. G 84 02 839 to Degussa discloses a clamp wherein the holder and the confining member comprise end portions and legs which cooperate to urge the holder against the confined pipe. The end portions and the legs constitute wedges and the legs of the confining member are forced over the end portions of the holder. This publication specifically points out that the confining member cooperates with the holder to ensure a reliable and pronounced retention and confinement of the pipe.
French Pat. No. 1,559,036 to Dom discloses a clamp wherein the holder and the confining member cooperate to forcibly confine the pipe between them. To this end, such parts are made of an elastic material and are dimensioned in such a way that they bear upon the external surface of the pipe. Reference may be had to the left-hand column on page 1 and to the resume of the patent.